Ignition-arch for furnaces.



W. M. DUNCAN. IGNITION ARCH POB. FURNAGES.

' rrmuumx Hmm AUG. 1s, 1911.

Patented May 2.1, 1912.

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W. M. DUNCAN.

IGNITION RGB Fon FURNAcEs. y APPLIOATIOH FILED AUG. 1B, 1911.

1,027,326. mummy 21, 1912.

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- UNITED STATES WILLIAM MILLE-:u DUNCAN, ornmomILmNoIs.

IGNITION-ARCH FOR FURNACES.

Specification of Letters Patent.

Patented May 21, 1912.

Applicationled August 18, 1911. S-erial No. 6454,733.

, monly comprise pluralities of rows of heat radiating blocks mounted onsuitable sup-v ports to which they are fitted in a manner to'permit theready mounting of the blocks Arches of this descriptioncom-l and theirremoval when they becomev impaired by subjection to heat inthe furnace.

It is 'a fact well known that the heat radiatingblocks at the rear endsof the ignition arches become impaired much more rapidly than do t-heblocks in front ofthem, and also that when such impairment of therearmost blocks occurs, there is frequently, if not usually, suchimpairmentl of the block supporting members as to render them unfit toreceive new. blocks it may be desired to substitute for those that havebecome impaired.

The object of my present improvement is to provide in connectlon Withthe main block supporting members ofI 4an ignition arch auxiliaryblock-supporting members adapted to receive the rearmost -heat radiatingblocks, and which auxiliary supporting members are separable from themain supporting members, thereby making it possible to replace them bysimilar auxiliary supporting members when those previously in use havebecome unserviceable.

Figure I is a view partly in side elevationand partly in longitudinalsection of an lock supporting members and a fragment .of one of the mainblock supporting members, the parts being shown separated from eachother.

y In the accompanying drawings :-`A and ignition arch containingjmyimprovement,

B -designate the transversely ."arranged heat blocks A being thoseentering into the structureof the arch throughout its main and front endwhile the blocks B are those lo# are the most liable to become injuredor Impaired by the greater heat they are subjeeted vto as compared withthe heat to which The heat radiating blocks are provided withlongitudinal perforations extending therethrough and" they are arrangedin rows 'exgrate. The longitudinal perforations a in the blocksA'receive main supporting rods 1 on which the blocks A are threaded. Themain block supporting rods are shown in the drawings, (see Figs. I andII), of tubu- Alar form, and they are preferably made of this form' topermit circulation of air therethrough in order that the rods willwithstand greater heat t-han they would without circulation of airthrough them.` The main supporting rods are suspended from suit ablesupports, such as beams 2, by suitable hangers 3 held in engagement withthe beamsk in .any suitable manner. The longitudinal perforatins in theheat radiating blocks B receive auxiliary supporting rods 4 that areremovably connected to the' main supporting rods A. These auxiliarysupport-ing rods are preferably tubular'to persame object in view asthat sought in making the main supporting rods tubular. Each auxiliaryblock supporting lrod is provided with a reduced inner end providing astem rod and which extends forwardly from a shoulder 6 on the rod. Theauxiliary sup'- 5 of the former into theL latter until the shoulders 6of the auxiliary support-ing rods abut against the rear ends of the mainsupporting rods, as seen in Fig. II, subsequently to which the auxiliarysupporting rods -4 will remain in alinement with the main supportingrods 1 and the joined thereon.

It will be noted on referring to Fig. II thatthe main block supportingrods l project only to the rearmost blocks A and that the remainder ofthe blocks are subjected.

tending longitudinally above the furnace mit circulation of airtherethrough with the 5, of` less diameter than the body of thesupporting rods will serve as units for the support of heat radiatingblocks mounted' -radiating blocks of `my ignition Varch, the

cated at the 'rear end of therarch, and which qporting rods 4 areconnected to the main supporting rods l by slipping. the stemslconsequently should the auXiliary supporting rods 4 be so impaired byheat as to be rendered unfit for use, the rear portions et' the mainsupporting rods l are not subjected to a suiiicient degree of heat toimpair them, and they therefore remain in serviceable condition toreceive new auxiliary supporting rods. Therefore, when there is occasionfor replacement of the rearmost blocks B and the auxiliary supportingrods supporting them, such replacement may be readily carried out by thesimple acts of `removing the blocks B, the auxiliary supporting rods,and the substitution of new auxiiary supporting rods and new blocks B.

I claim l. An ignition arch comprising longitudinally arranged tubularmain 'supportingl rods locatedat the frontend of the. arch, heatradiating blocks mounted on said main supporting rods, longitudinallyarranged auxiliary supporting rods having reduced ends and located atthe rear end of t-he arch and having their reduced ends inserted in saidmain supporting rods, and heat radiating blocks mounted on saidauxiliary supporting rods.

2. An ignition arch comprising longitudinally arranged tubular mainsupporting rods located at the front end of lthe arch, heat radiatingblocks mounted on said main supporting rods, longitudinally arrangedtubular auxiliary supporting rods having reduced ends and located at therear end of the arch and having their reduced 'ends in- 35 serted insaid main supporting rods, and heat radiating blocks mounted on saidauxiliary supporting rods.

WILLIAM MILLEN DUNCAN.

In the presence of- A. B. SrRA'rroN, Gr. D. EUNCAN.

